Basement finishing in Cincinnati

41%⁸ of homes in the city were built before 1940. Their basements were dug for a coal furnace and a laundry tub, and the foundation walls are often stone or brick, which can let damp through.

Measure before you design. The Residential Code of Ohio generally requires habitable space to have a ceiling at least 7 feet high, but lets habitable space created in an existing basement have a ceiling of 6 feet 8 inches, with beams, ducts and other obstructions allowed down to 6 feet 4 inches.¹⁴ Old drain lines and ducts often hang below the joists, so have the company show what must be moved.

Before turning basement space into living space, the EPA advises checking it for leaks and other signs of moisture and fixing any moisture problem first, because damp basements promote mold and other biological growth.¹⁷ The EPA warns that carpet on a basement slab can stay damp from water or vapor coming up through the concrete, or from room moisture condensing on a slab that is colder than the air, and either can lead to mold.¹⁷

EPA's Map of Radon Zones places Hamilton County, Ohio, in Zone 1, the highest-potential zone, along with Butler County to the north, while Clermont County to the east is in Zone 2.³ On the EPA's radon map, Zone 1 has the highest potential, with average indoor levels that may top 4 pCi/L, Zone 2 a moderate potential of 2 to 4 pCi/L and Zone 3 a low potential under 2 pCi/L; the EPA says homes with elevated radon have been found in all three zones and all homes should be tested.¹⁸ A zone tells you to test, not what your house will show.

The Ohio Department of Health recommends testing every occupied ground-contact structure in Ohio for radon, and says testing is the only way to know the radon level in your home.¹⁹ The EPA recommends testing for radon on the lowest lived-in level, so a basement that hasn't been tested should be tested before it is remodeled; fixing a radon problem is usually easier and cheaper before the basement is finished.¹⁷ The EPA's guidance is to fix your home if radon tests at 4 picocuries per liter or higher, and to consider fixing it between 2 and 4.²⁰

If a system is needed, the pipe through the slab and the fan are easier to place before new walls go up. The Ohio Department of Health recommends retesting a single-family home for radon every two years, or after significant renovations that may change how air moves inside it.¹⁹ Because finishing a basement changes how air moves through a house, the EPA advises having a professional check afterward that new and existing combustion equipment is not backdrafting.¹⁷

In a hard storm, an overloaded public sewer can push water back up through a basement floor drain. MSD's Sewer Backup Program, run under a federal consent decree, investigates, cleans up, reimburses qualifying damage and provides prevention devices when a building backs up because of too little capacity or certain maintenance problems in the public sewer; private sewer backups and overland flooding don't qualify.²¹

MSD says a sewer backup must be reported within 48 hours of discovery to be considered for reimbursement, and a damage claim must reach MSD within two years of the backup.²² A property with two or more backups in five years caused by too little capacity in the MSD public sewer may qualify for a backup prevention device installed at no cost.²²

MSD says a building owner owns the building sewer and is responsible for keeping it clear and repairing breaks on private property, and it suggests asking a plumber about a backflow valve on that line.²² If water has ever come up through your floor drain, settle the valve question before you finish the room, and ask your insurer what a sewer-backup endorsement covers.

The Residential Code of Ohio requires every sleeping room, including one in a basement, to have at least one operable emergency escape and rescue opening, unless the home has an automatic sprinkler system and the basement has the means of egress the code spells out.¹⁴ Under the Residential Code of Ohio, an escape opening needs a net clear opening of at least 5.7 square feet, or 5 square feet at grade floor or below grade, with a net clear height of at least 24 inches and a net clear width of at least 20 inches.¹⁴

The original windows in an older Cincinnati basement are usually narrow strips set high in the wall, so a legal bedroom tends to mean saw-cutting the foundation and digging an outside well. If the room is for a tenant or relative living on their own, read the Cincinnati rental conversion guide first, because a separate unit brings in the city's ADU and rental registration rules.

More than one in four adults 65 and older fall each year.²³ Steep, narrow basement stairs with a single rail are common in older Cincinnati houses.

Add a graspable rail on both sides if the width allows, light switches at the top and bottom, and bright, even light on every tread. If an older relative will live down there, ask about aging-in-place experience. NAHB's Certified Aging-in-Place Specialist (CAPS) credential trains remodelers in home modifications for aging in place.²⁴

Call the number on this page and your recorded call goes to one independent company that handles basement finishing in the Cincinnati area. You discuss water, radon, layout and cost with them directly.

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Before you sign or pay, check the company yourself. Every contractor working within Cincinnati city limits must keep a current city registration, renewed each year, and the city cannot issue building permits until all the contractors on the job are registered.¹⁵ Check an Ohio license